That's not really a valid question. I want you to be a beautiful girl and what do I get: a picture of a betautiful girl. Still, that doesn't prove you're not really a squirrel. Maybe our perception of ourselves is influenced by what we want to see. And also, maybe our perception of what a squirrel is, is wrong. How can you really be sure of what is and what is not. After all, we only depend on our eyes, ears, nose and sense of touch to tell us stuff. Now, can be really depend on them? Who knows? They may be giving all the wrong info. Maybe you all don't even exits. Maybe I AM a squirrel and the only one of the face of the earth. A squirrel who wants to be a human, with many humans with me to chat with etc.
What do we really know?